Impound water comprises drainage water or runoff water from any number of activities including agricultural activities. Impound water contains any number of contaminants including total dissolved solids, total suspended solids, settleable solids, organic compounds, minerals, heavy metals, and biological substances. Biological substances can include biological organisms, microorganisms, viruses, and the substances that they produce or secrete such as exopolymeric substance. Exopolymeric substance includes extracellular polysaccharides, lipopolysaccharides, glycolipids, lipids, humic substances, proteins, peptides, and nucleic acids and can form a sticky substance that fouls filtration membranes used in impound water treatment. Agricultural impound water that contains soil amendments tends to have higher concentrations of exopolymeric substance leading to increased biofouling of microfiltration membranes during treatment of the impound water.
While some conventional methods have been developed to treat agricultural impound water, these conventional methods are ineffective in removing exopolymeric substance. The exopolymeric substance consequently fouls microfiltration membranes and leads to increased back pressures and lowered flow rates across the microfiltration membranes. In some cases, biofouling of the microfiltration membrane continues until microfiltration is completely impeded.
Thus, while a variety of methods currently exist for treating agricultural impound water, challenges still exist, including those listed above. Accordingly, it would be an improvement in the art to provide methods and systems for reducing biofouling of microfiltration membranes that are biofouled with biological substances during treatment of agricultural impound water.